Python Django ORM注释布尔字段,用于定义团队的用户成员
型号.pyPython Django ORM注释布尔字段,用于定义团队的用户成员,python,django,django-orm,Python,Django,Django Orm,型号.py from django.db import models class UserGroup(models.Model): members = models.ManyToManyField(User, related_name='members', through='UserGroupMember') class UserGroupMember(models.Model): user = models.ForeignKey(User) usergroup
from django.db import models
class UserGroup(models.Model):
members = models.ManyToManyField(User, related_name='members', through='UserGroupMember')
class UserGroupMember(models.Model):
user = models.ForeignKey(User)
usergroup = models.ForeignKey(UserGroup)
class Cohort(models.Model):
user_groups = models.ManyToManyField(UserGroup)
class Team(models.Model):
cohort = models.ForeignKey(Cohort)
members = models.ManyToManyField(User, related_name='team_members', through='TeamMembers', blank=True)
class TeamMembers(models.Model):
team = models.ForeignKey(Team)
user = models.ForeignKey(User)
单个用户只能是队列中一个团队的一部分
我想注释新字段(布尔值),它告诉您是分配给队列中某个团队的用户,类似于:
User.objects.filter(
members__cohort=cohort
).annotate(
is_team_member=...
)
我使用的是Python 2.7.13和Django 1.9.8。谢谢。我通过加入
队列
模型并使用条件表达式成功地解决了这个问题:
from django.db.models import Case, When, Value, IntegerField
users = User.objects.filter(
members__cohort=cohort
).annotate(
is_team_member=Case(When(team_members__cohort=cohort, then=Value(1)), default=0, output_field=IntegerField())
)
现在,我可以轻松筛选,例如,属于某个团队的用户:
users.filter(is_team_member=1)